The environmental footprint of beef production

The sustainability of animal agriculture is currently one of the most highly-debated issues within food production. Consumers often have an ideological view of the perceived advantages of historical small-scale agrarian systems compared to modern agriculture, which, in combination with a renowned desire to understand how food is produced, leads to the supposition that the “good old days ” were environmentally superior. Through improvements in genetics, nutrition and management between 1977 and 2007, the U.S. beef cattle industry increased average slaughter weight (1,338 lb in 2007 vs. 1,032 lb in 1977) and overall growth rate (2.60 lb/d in 2007 vs. 1.59 lb/d in 1977) which resulted in the total average days from birth to slaughter being reduced from 609 d (1977) to 485 d (2007). In combination, these productivity improvements resulted in considerable reductions in feed (19%), land (33%), water (12%) and GHG emissions (16%) per lb of beef over the thirty-year time period. A small yet vocal section of the population advocate for a whole-scale return to the pasture-based production systems that predominated in the first half of the twentieth century within the United States, yet the 135 million acres of increased land required to maintain current U.S. beef production from a wholly pasture-based system would render whole-scale conversion practically impossible (Capper, 2012). If such conversion did occur and annual beef production was maintained at 26.1 billion lb, the increase in carbon emissions would be equal to adding 26.6 million cars to the road per year (Capper, 2012). Pelletier et al. (2010) and Capper (2012) also demonstrated that GHG emissions per unit of beef were greater in pasture